Does folic acid have any effect on erectile dysfunction? Possibly a small one, but it is not proven. Men with erectile dysfunction tend to have lower blood folate than men without it, and in one randomised trial folic acid added to tadalafil improved erection scores more than tadalafil alone. No trial has shown that folic acid on its own treats ED, and a low level in men with ED does not prove that it caused it.
Do men with ED have lower folate?
On average, yes. A meta-analysis of six studies with 1,842 men found higher folate in men without ED, and a wider gap the more severe the ED (Xu et al., Andrologia 2021); a second, of nine studies, reached the same result (Zhang et al., Sex Med 2021). The studies behind them are small comparisons — 60 men with ED against 30 without in Egypt (Attia et al., 2019), 31 against 31 in Italy (Sansone et al., 2018). In the Egyptian study, low folate went along with smoking, age, high blood pressure, high cholesterol and diabetes, all linked with ED, though the gap held after allowing for most of them. A US diet survey of 3,875 men linked more dietary folate with less ED only in subgroups, such as men aged 60 or younger and men without heart disease or high blood pressure (Wang et al., 2024).
Does taking folic acid improve erections?
There is one small randomised trial, and it tested folic acid as an add-on to an ED medicine.
| Study | Who and what | Result |
|---|---|---|
| Hamidi Madani et al., 2013 — randomised, double-blind | 83 men with type 2 diabetes and ED: tadalafil 10 mg every other day plus folic acid 5 mg a day, or plus placebo, for 3 months | Erection scores rose 5.1 points with folic acid and 1.7 with placebo |
| Elshahid et al., 2020 — no placebo group | 50 men with ED from blood-vessel problems: folic acid daily for 3 months | Median scores rose from 6 to 14 |
| Lombardo et al., 2010 — no control group | 18 men whom sildenafil had not helped, with low folate and high homocysteine: sildenafil plus vitamin B6 and folic acid for 6 weeks | 16 of the 18 improved |
A 2021 review of combination treatments found that adding folic acid to an ED medicine improved scores, but that the result "was based on only 1 study" (Mykoniatis et al., JAMA Netw Open 2021). Studies without a placebo group cannot separate folic acid's effect from the ED medicine, time or expectation. The trial dose, 5 mg a day, is five times the upper limit healthdirect sets for folate, so it is not one to copy without a doctor.
Is homocysteine the link?
That is the theory: folate helps lower homocysteine, which studies find higher in men with ED. It is unproven, and in the Italian study folate and homocysteine levels were not correlated (Sansone). The homocysteine studies are covered in can low or high vitamin B12 cause erectile dysfunction?
How much folate do men need, and how much is too much?
Men need 400 micrograms a day, which most can get from food: green leafy vegetables, legumes, citrus fruit, avocado, eggs and bread — in Australia, folic acid is added to all bread-making flour except organic and gluten-free flour (healthdirect — Folate). The upper limit is 1,000 micrograms a day, because high levels can cause or worsen a vitamin B12 deficiency (healthdirect — Vitamin B and your health). If you take a multivitamin, check how much it already contains.
Who runs low on folate, and should you get tested?
Folate deficiency is one of the most common vitamin deficiencies in Australia. The men most at risk are people having kidney dialysis, people who drink too much alcohol, people with liver disease and those on certain medicines, such as some used for seizures. It can cause folate deficiency anaemia, with extreme tiredness, mouth ulcers and muscle weakness. A blood test shows your level, and a deficiency is usually treated with folic acid tablets for a few months (healthdirect — Folate). Anaemia and erections are covered in can low iron or anaemia cause erectile dysfunction?, and drinking in can alcohol cause erectile dysfunction?
Can you take folic acid with Viagra or Cialis?
Neither Australian leaflet names folic acid, and in the trials above it was taken with tadalafil or sildenafil; in the randomised trial "Both folic acid and tadalafil were well tolerated by all the patients" (Hamidi Madani). Both leaflets ask you to tell your doctor or pharmacist about "any medicines, vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop" (Viagra CMI; Cialis CMI).
The short answer
Men with ED tend to have lower folate, and one small trial found folic acid helped a little when added to tadalafil, at a dose above the recommended limit. That is not enough to call it a treatment. Eat folate-rich food, get tested if you are at risk of deficiency, and see your GP about the usual causes of ED. Other vitamins are in can a vitamin D deficiency cause ED? and the best vitamins and supplements for erectile dysfunction; more in our guide to lifestyle and erectile dysfunction.
